Local health officials are worried about the spread of the Zika virus in the U.S. and specifically Southern California.
Zika virus can cause birth defect
The Zika virus is especially a concern to pregnant women because the virus can cause a birth defect called microcephaly.
"Which is to say a child with a damaged, shrunken brain at birth," explained Dr. Brian Johnston, the head of emergency medicine at White Medical Center.
Symptoms include fever, joint and muscle pain
Johnston said non-pregnant people can suffer relatively mild symptoms like a fever, joint and muscle pain, and redness of the eyes.
The WHO warned the Zika virus is troubling to North America because it hasn't been spotted in the area, and there's no immunity.
Health officials also said number of mosquitoes are increasing.
"It's in Ecuador and Peru and Central America," Johnston said. "And so it's something that's coming our way, and we need to be aware of it."
Zika virus transmitted through Aedes mosquito
The Zika virus can only be transmitted through one type of mosquito called the Aedes mosquito. The breed is much more aggressive than mosquitoes Southern Californians typically see.
"They are more aggressive. They will come into a building. They bite during the day. They fly at lower altitudes so children are at greater risk," Johnston said.
How to protect yourself from Zika virus
Johnston said there are things you can do to protect yourself from mosquito bites, like wearing long pants and sleeves and eliminating standing water where mosquitoes can breed.
Health officials also urge checking window screens and the seals around windows. If you're traveling to areas where the Zika virus is present, experts recommend using a mosquito net.